Modern network communication systems are generally of either the wired or wireless type. Wireless networks enable communications between two or more nodes using any number of different techniques. Wireless networks rely on different technologies to transport information from one place to another. Several examples include, for example, networks based on radio frequency (RF), infrared, optical, etc. Wired networks may be constructed using any of several existing technologies, including metallic twisted pair, coaxial, optical fiber, etc.
Communications in a wired network typically occurs between two communication transceivers over a length of cable making up the communications channel. Each communications transceiver comprises a transmitter and receiver components. A fault along the communication channel causes a disruption in communications between the transceivers. Typically, it is desirable to be able to determine when a fault occurs in the channel. Once a fault is detected, it is desirable to determine information about the fault, such as its location along the channel.
The deployment of faster and faster networks is increasing at an ever quickening pace. Currently, the world is experiencing a vast deployment of Gigabit Ethernet (GE) devices. As the number of installed gigabit Ethernet nodes increases, the need for reliable, comprehensive and user-friendly cable diagnostic tools has become more important than ever. The wide variety of cables, topologies and connectors deployed results in the need for non-intrusive identification and reporting of cable faults.
As part of a diagnostics capability, an important feature in the Ethernet plant is the ability to measure the length of the cable between two edges. This could be achieved in two different modes of operation: a non-active link mode and an active link mode of operation.
Performing cable diagnostics in active mode is problematic as during this mode of operation, data is sent in both directions. Furthermore, unlike in the non-active mode, the transmission of test pulses is not possible.
Thus, there is a need for a cable diagnostics mechanism that provides a means of performing cable diagnostics that overcomes the disadvantage of the prior art. The diagnostics mechanism should be capable of estimating the length of an Ethernet cable between two points. The mechanism should also be able to estimate the length of the cable while in the cable is in an active mode of operation. Further, it is desirable that the diagnostic mechanism be incorporated into a conventional communications transceiver without requiring extensive modifications to the transceiver.